Car is a 00 civic si running a s300 p28. Getting fuel cut at 2000rpm. Engine wont rev past 2000rpm due to cut. Down shifting from 5th to force engine over 2000rpm will also result in a cut. So there really isnt a window within a specific rpm range that the problem lies in. Fuel cuts out untill engine revs go down to idle Then they turn on again. Dont have a laptop to datalog and havent had time haul it to nearest shop(160mi). Ive just been using a multimeter to measure sensors. Afr gauge shows that its not running lean. Ive already replaced ignition parts. Fuel pressure is normal. Problem dissappears for a short while (about a week) when ecu is reset. Does that indicate anything? Car starts and idles just as it should. When the problem is gone car runs great.

 

Sounds like its on a basemap you're trying force through. You need to give background of the ECU,where/how it was tuned, etc.

Get to the tuner. Before you break something.